The purposes of the D-4-R zone are to promote the development of high-density residential and mixed-use neighborhoods on:

Massachusetts Avenue between Thomas Circle and New Jersey Avenue, N.W.

The Mount Vernon Triangle neighborhood located between New York, New Jersey, and Massachusetts Avenues, N.W.; and

The blocks between Massachusetts Avenue, N.W. and Judiciary Square.

A building with frontage on a designated primary or secondary street shall meet the design requirements on Subtitle I § 602. A building in the D‑4-R zone fronting on a designated primary street segment in the Mount Vernon Triangle Principal Intersection Area Sub-Area shall conform with the design requirements in Subtitle I §§ 612.5 and 612.6

A building in the D-4-R zone may generate or use credits in accordance with Subtitle I, Chapters 8 and 9, which explains the credit system relating to Transferable Development Rights (“TDR”) or Combined Lot Development (“CLD”) rights. The D-4-R zone is not subject to the Inclusionary Zoning provisions of Subtitle C, Chapter 10.

A building on a lot in the D-4-R zone must provide the equivalent of at least 4.5 Floor Area Ratio (“FAR”) of residential use before any non-residential uses may be provided on the lot, unless the development meets one of the exceptions in Subtitle I § 532.1. The permitted height of a building in the D-4-R zone is based on the right-of-way width of the street upon which it fronts, as detailed in the table below.

A front setback is not required, except as otherwise required by Subtitle I § 612 in the case of a designated primary street segment.

1 The maximum permitted density for a building shall be the density achievable within the height and bulk permitted by the zone and any applicable sub-area regulations: (a) If all of the building’s FAR is devoted to residential use; (b) If all FAR exceeding the non-residential density permitted in Subtitle I § 531.5 is devoted to residential use; or (c) If conditions (a) or (b) are not satisfied, through the use of credits pursuant to Subtitle I, Chapters 8 and 9.2 Unless: (a) The residential requirement is reduced or eliminated by the provisions of Subtitle I §§ 200.3, 200.4, 305.2, or 531.3; (b) The residential requirement is reduced by up to 1.35 FAR through constructing or financially assisting affordable housing pursuant to Subtitle I § 305.6; or (c) If modified through the credit procedures provided in Subtitle I, Chapters 8 and 9.3Subject to applicable regulations governing courts, side or rear yards, front setback or build-to lines, easements or historic preservation.4Unless modified in in Subtitle I, Chapter 3 or by regulations governing a specific Downtown sub-area.5 No parking is required in this zone, but parking spaces provided are subject to Subtitle C, Chapter 7.